The present invention relates to a sheet feeding device for feeding sheets from a tray one by one, and an image forming apparatus including the same.
A printer, facsimile apparatus, copier or similar electrophotographic image forming apparatus has a photoconductive drum or similar image carrier for forming a toner image thereon. A sheet feeding device built in the apparatus feeds sheets one by one to the image carrier, so that toner images are transferred from the image carrier to the sheets. Generally, the sheet feeding device is made up of a sheet feeding and separating section and a sheet conveying section. The feeding and separating section feeds the top sheet from a stack loaded on a tray while separating it from the underlying sheets. The conveying section conveys the separated sheet to an image transfer station adjoining the image carrier. The problem with the conventional sheet feeding device is that the feeding and separating section and the conveying section are each implemented as an independent unit. As a result, the entire device needs a great number of parts and obstructs the compact design of an image forming apparatus. Moreover, an exclusive drive transmission mechanism must be assigned to each of the two sections, increasing the cost of the apparatus. In addition, it is difficult with the conventional device to reduce a load to act on a sheet being conveyed. Therefore, sure sheet separation and smooth sheet pay-out and conveyance are difficult to achieve.